3
Introduction
Please Note!
This manual assumes use of microphone-level inputs and line-level output
for most typical SmartMixer applications. However, all inputs may be
individually switched via the included AT-DMM828 Control Software to
achieve any combination of mic-level and line-level inputs.
Signal flow can be changed via the included AT-DMM828 Control Software.
Refer to Software Manual for more information.
About the AT-DMM828
AT-DMM828 is a microprocessor-controlled, programmable, automatic-
switching eight-channel matrix mixer. It can be used with low-impedance
either dynamic or condenser microphones (including wireless microphone
systems), as well as line-level sources.
AT-DMM828 is designed to improve audio quality in broadcast, sound-
reinforcement and recording applications. One way it achieves this is
by keeping the number of open microphones to minimum, thus reducing
background noise, feedback and other distractions, while providing instant,
completely transparent switching between channels.
Each of the eight balanced inputs provides switchable 48Volt phantom
power; attenuation is also selectable on each input to allow use with line-
level signals. The mixer's outputs are balanced and non-inverting. All audio
connections terminate in block screw connectors.
Up to 16 units of AT-DMM828 (a total of 128 channels inputs) can be daisy-
chained via CAT6 cable, which carries control bus, audio, and configuration
data between mixers.
Multiple mixers linked in this way will operate as if they are a single mixer.
Therefore, microphones activated on any mixer will cause the appropriate
switching functions to occur. The link connectors are not compatible with
LAN.
Each AT-DMM828 includes two separate external control system interfaces:
Individual channel contact closures (via DB25 connector) and PC control (via
RS232 connector or USB). The RS232 connector can also be used to connect
an external control system (e.g. Crestron
®
or AMX
®
) using “open disclosure
communication protocol” to control the mixer.
AT-DMM828 Features
• Eight balanced inputs allow to be used with either mic-level or line-level
signal.
Each input provides:
° 48V phantom power (individually selectable)
° Individual gain and sound volume controls
° Gate attenuation adjustable (0 dB to full mute in steps of 1 dB)
° Gate hold time adjustable (0.1 sec to 6.0 sec in steps of 0.1 sec)
° Mic on threshold level adjustable (Auto/Manual)
• DSP algorithm
° Signal level meter (Peak/RMS)
° Signal generator (Sine wave/Pink noise/White noise) *input
channel only
° Parametric EQ (3 band/4 band)
° Filter (Low pass/High pass/Low shelving/High shelving/Notch/All
pass)
° Limiter
° Delay *output channel only
° 8×8 full matrix-mixing (can be extended to 128×8 matrix-mixing)
• Selectable NOMA (Number of Open Microphones Attenuated)
° Automatic gain adjustment as each microphone is activated
• Selectable manual mode overrides automatic functions
• Linking capability for up to 16 units (up to 128 inputs)
• Selectable external connector’s pin assignment
° Gate status output (using for the Camera moving)
° Gate On/Off (using for input gate control by tactile switch)
° Mute On/Off /Toggle (using for channel level control by tactile switch)
° Volume Up/Down (using for channel level control by tactile switch)
° VCA function (using for channel level control by external
potentiometer)
• Compatible with Crestron
®
or AMX
®
systems
• All settings can be adjusted or modified through AT-DMM828 Control
Software
• Mounts in a single U 19” rack space (EIA Standard)
